Sprag type one-way clutch



Oct. 21, 1952 A. Y. DODGE SPRAG TYPE ONE-WAY CLUTCH Filed Feb 19, 1948 This invention relates I mere particularly to a construction which will serve a -one' way clutch and as a bearing.

-' one-way clutches of the tiltable gripper type liave heretofore been proposed, but in these constructions it'has been necessary to provide sepamay' func'tionasbearing surfaces. It is-anoth'er object to provide a one-way 'clutch' in which tilting of the grippers toward Patented oct. 21,;19 52 .I

2,614,669 r I SPRA'G'TY'PE oNEQWAY (moron 7 Adiel Y. Dodge, 'Reekfora'ni.

to' one -way clutches and rate mechanism to formbea'ring surfaces so'that th'e unit=can"act"as a bearing during overrunnin'g. It is one of the objects of the present invention 'to p'rovide a one-way clutch in which the surfaceso'f' the tiltable grippers themselves their disengaged position is positively limitedso that the grippers mayfunction as bearing members'. Limiting of the gripper'tilting maybe accomplishedin various ways includingthe provision of interengaging shoulders on the grippers themselves the provision of a cage having cross bars to engage and limit tilting of the grippers, andtheprovisionof annular stop rings fitting loosely "into openings in'the grippers.

" Still another object is to provide a one-way clutch in which the grippers are urged toward *engaged position by annular springs and are positively limited in their movement toward disengaged position. This construction prevents excessive deflection of the springs which might re- 'sult in damage thereto.

A further object is to provide a one-way clutch in which the grippers are'controlled 'by radially spaced annular springs. Preferably the outer- I 'most spring has an excessive length so that it is under compression and will urge the outer ends of the grippers toward the outer race while the inner spring is under tension to urge the inner ends of the grippers toward the'inner race. This construction holds the opposite ends of the grippers invfrictional contact with the races so. that upon a reversal of, torque from the overrunning pp1 tie February 19,1948, SerialNo. 9,458 I 4 Claims. (Cruz-45.1)

prises an outer annular. race IO. and an inner race H. The races have coaxial'ciylindricalfac- 'ing surfaces between which are-arranged-a series of tiltable grippers H. The ends of the grippers are, eccentrically curved so that" when they are tilted counter-clockwise as seen in Figure 1 they will grip the races and .hold them against relative rotation and when they are tilted clockwise they will release the races.

According to the present invention, tilting of the grippers toward thereleased position is limited by forming the grippers with interfitting shoulders. As shown, eachgripper is formed at one side with an outwardly facing shoulder 13 and at its opposite side with an inwardlyfacingshoulder M. When the grippersare arranged between the'ra'ces, the shoulder iii-on one gripper will underlie the shoulder I4 on the next adjacent gripper. 'With'this construction the grippers can tilt counterclockwise freely, but

when they. tilt clockwise, the shoulders l l will engage the adjacent shoulders I3 positively to limit tilting. Preferablythe shoulders are so proportioned that when the grippers are in their extreme release position their ends will have a. slight clearance atthe race surfaces sufiicient to permit an oil film. With this construction the grippers will holdthe races accurately centered and'their ends form rigid bearing surfaces on which the races may ride. Therefore; in the overrunning direction the grippers function as bearingmembers similar to slipper bearings.

The grippers are preferably urged to tilttoward 'theirengag'ed position by annular coil springs l5 and 66. As shown} the spring 'I5'extends through openings in the grippersadjacent their outer ends, and the spring I (5 entends through similar openings in the grippers adjacent their inner ends. To urge the grippers toward endirection the grippers will engage the races H rapidly;

The above and other objects and advantages "of the invention will be more readily apparent when read in connection with the accompanying drawing, in which- Figure 1 is a side elevatiorn with parts in section of a one-way clutch; embodying the invention;

' Figures 2 and 3 are views similar to Figure 1' illustrating alternative constructions; and

Figure 4 is a section on the line 4-4 of Figure 3.

The construction as shown in Figure 1 comga ecl posit on the outer s ring i5 is formed with aslightlv excessive length so that it is under compression and the inner spring is under ten-' sion. Thus the outer spring ten-dsto' force the outer ends of the grippers into engagement with the outer race and the inner spring tends to draw the inner ends of the grip ers into en agement' with the inner race. With thisconstruction the grippers tend to maintain frictional contact withthe races at their'opposite ends. 1 Therefore, upon relative rotation of the races in the "locking direction, the friction forces of the races on the ends of the grippers will assist in tipping them toward their gripping position so that a very rapid engagement is'insured with a minimum of backlash.

a rectangular notch 29.

The construction of Figure 2 includes an outer annular race I! and an inner annular race l8 between which are arranged a series of tiltable grippers i9 having eccentrically curved ends.

The grippers iii are formed with fiat parallel sides and are spaced by cage cross bars 2| also having fiat parallel sides. The grippers may be urged to engaged position by inner and outer annular springs 22 and 23 which function in the same manner? as" the springs l and L IS. of! Figure 1. Preferably the springs and openings are arranged so that when the grippers are tilted toward their disengaged position the springs will be bent slightly as more particularly dGSClibEdi and claimed in the patent to Swenson, No.

In the construction of FigureZ, .the cage bars 2! lie at such an angle to a radius through them that they will engage the flat sides of the adjacent grippers and limit tilting thereof toward the disengaged' position. Thus the. gripperssprovide 'rigid bearing surfaces of. the. slipper type during overrunning.

additional feature. of thisconstruction which is also present in Figurev 1 is that the limitingoi'; the tilting; ofthe grippers prevents excessive tilting which might damage thesprings. Without some means: to limit tilting, it is apparent that excessive; tilting of the. grippers mightbend the-springs'to anextent which would each. other: without interfering in any way' with theirrtiltingmovement. The grippers areurged toward engagedposition'by inner and outer coil springs 21' and 28 which function in the same .manner as'the springs 15 and I6 of Figure-1.

To. limit tilting movement of the grippers, eachgripperis formedin one or both ends with Annular rings 31 of rectangular section are fitted. into the notches and are; narrower than the notches. to leave a clearance so that the grippers may tip. When the; grippers'are inthe position shown in Figure 3,:the:0pposite ends of. the notches engage the rings 3| so thatthegrippers cannot tiltfurther clockwise: Thus their tilting is-positively limited so-that they will provide rigid-bearingsurfaces onwhich the racesmay run during overrunning;

the'scope-of the invention, reference being bad for this. purposeto the appended claims;

' What is claimed'is:

1. A one way clutch comprising inner and between the races having eccentrically curved ends -to=grip the races. when tilted in one direction and to release the races when tilted in the other direction, stop means engageable with the grippers to limit tilting thereof in said other direction, the grippers having an outer series of openings therein adjacent their outer ends and a second series of openings-therein adjacent their inner ends, and annular coil springs in the series of openings, the spring in the outer series of openings tending to expand and the spring in the inner'seriesbf openings tending to contract thereby to hold'the ends of the"gripp'ers 'in engagement with the races respectively.

2. A one way clutch comprising inner and outer coaxial; races, a series of tiltable grippers between the races having their ends eccentrically=-curved to grip the races when tilted in one .directionandto.release the races when tilted in the other direction, the grippers having an outer series of openings therein adjacent their outer ends and an inner series of openings therein adjacent their inner ends; and annular coil springs. extending? through. the respective series of openings, the outer spring being under compression' to urge; the grippers outward and. the inner springbeing. under tension to. urge; the grippers inward thereby to hold the endsioi the grippers in contact with. theraces.

3. A one: way clutch comprising. inner: and outer coaxial races; a series: of tiltablegrippers between. the races having; eccentrically curved ends to griptheraceswhen tiltedin one-direction and to release'the raceswhen tilted in-v the other direction, the grippers being; formed with inwardly facing shoulders at. onei-sidaandout.- wardly-facingshoulders at the other side; to engage the shoulders. on: adjacent grippers and limit'tilting: in. said other direction, the grippers having vopeningstherethrough; and an annular spring threaded throughv the openings. in -the grippers-andurgingthem in said one-direction:

4. A one; way clutchcomprising: inner. and outercoaxial races, a series of. tiltable. grippers between the races having eccentrica'lly curved" ends: to grip the races when tiltedin one direction and to release" the races when tilted ,in: the other direction; the grippers being-formed-with with inwardly-facing shoulders at one side'and outwardly facing'shoulders' at the other side to engage the: shoulders." on adjacent grippers-and limit tilting in said other direction. thegrippers having inner and .outer series of openings therein, and-annular springs extending through the openings, the outer spring: being underv compression and the inner. spring being undentension.

ADIEL Y. DODGE;

REFERENCES CITED The following references are of record in" the file of this patent:-

UNITED STATES. PA'I'ENTS Number Name Date;

2,386,013 Swenson Oct".- 2,.1945 2,388,424 Lund. Nov. 6;" 19.45

FOREIGN PATENTS;

Number I Country Date 298,673 Great-'Britain= Oct. 15,1928 

